KENOSHA, Wis. (Court TV) — A man twice convicted of killing his wife with antifreeze is asking for a third trial, saying the evidence proves the victim killed herself.
Mark Jensen listens as the judge instructs the jury on day 1 of his murder retrial, Wednesday, Jan. 11, 2023, in Kenosha, Wis. (Court TV)
Mark Jensen, 66, was sentenced to life without parole for the murder of his wife, Julie Jensen, after two juries found him guilty.
At his first trial in 2008, the jury deliberated for 30 hours before finding the defendant guilty of first-degree intentional homicide, finding that he poisoned his wife with antifreeze and suffocated her with a pillow. Mark Jensen appealed the verdict and successfully argued that prosecutors should not have been allowed to show the jury a letter Julie Jensen had written and sent to the police saying that her husband should be the first person investigated if she died. The Wisconsin Supreme Court ruled the letter inadmissible hearsay. The second trial, held in 2023, ended with the same verdict and sentence.
An appeal filed by Mark Jensen’s new attorney claims the defendant’s 2023 attorneys were ineffective and requests an evidentiary hearing to support a new trial.
While the first appeal centered on the letter Julie Jensen sent to the police, the new appeal focuses largely on digital evidence.
At both of Mark Jensen’s trials, prosecutors argued that the defendant killed his wife to be with his lover — whom he later married. Investigators testified that for years before Julie Jensen’s death, Mark Jensen had targeted his wife with a campaign of “sadistic psychological torture,” involving pornography and spam phone calls, designed to make her appear mentally unstable. But Mark Jensen’s defense argued he had nothing to do with the harassment that he said drove her to take her own life.
At the 2008 trial, both the prosecution and defense stipulated that the searches on the Jensens’ home computer had been recorded accurately in the Central time zone. But in 2023, prosecutors brought in a new expert who said the searches were actually recorded in Pacific Time. Among the things searched was ethylene glycol, the poison in antifreeze that would later kill the victim.
WATCH | WI v. Jensen: Man Accused of Poisoning Wife (2008)
The new appeal claims that “incorrect timeline shifted critical searches on the home computer from times when Mark was away to times when he was home. That let the State tell the jury that Mark was home for all the ethylene-glycol searches and that Julie had no plausible way to have made them — an argument the correct timeline would have foreclosed.”
The appeal says that not only did Mark Jensen’s 2023 defense lawyers fail to properly question the change in the timeline, but they also failed to thoroughly investigate all the evidence on disks the prosecution shared in discovery. A postconviction investigation, the new motion argues, includes “chats and files on the disk showing that Julie used the computer when Mark was away, fabricated the harassment, and pulled the pornographic images from chat rooms she participated in.” While the state shared the information with the defense on a disk, Mark Jensen’s attorney argued that prosecutors had an obligation to specifically point out the exculpatory information.
At the same time someone used the Jensens’ computer to search “ethylene glycol,” someone also searched “nicotine as a poison.” At trial, prosecutors said that was further evidence that Mark Jensen was at the keyboard because he was a smoker and had a doctor prescribe a nicotine-replacement product for him the next day. But the defendant’s new attorney said in the motion for a new trial that the evidence suggests that Julie Jensen was the one using the computer. “While Mark was at work, Julie called [his doctor’s] office three times and the pharmacy once from the home phone; amid those calls, someone backed up the family computer’s Quicken program, which only Julie used; and the prescription was changed from an inhaler to liquid nicotine, which (unlike the inhaler) can act as a poison. The next day, when someone picked up the prescription, Julie withdrew $100 cash.”
Jensen is currently housed at the Oshkosh Correctional Institution, according to prison records.
